System and Method for Scrambling Using a Bit Scrambler and a Phase Scrambler

1. A method, in a multicarrier communications transceiver comprising a bit scrambler followed by a phase scrambler, comprising: scrambling, using the bit scrambler, a plurality of input bits to generate a plurality of scrambled output bits, wherein at least one scrambled output bit is different than a corresponding input bit; rotating, using the phase scrambler to reduce a peak-to-average power (PAR) ratio of a transmitted multicarrier signal, at least one constellation point associated with the at least one scrambled output bit, wherein the rotating is equal to 0 or π; transmitting the at least one scrambled output bit on a first carrier of the transmitted multicarrier signal; and transmitting the same at least one scrambled output bit on a second carrier of the transmitted multicarrier signal.

2. The method of claim 1 wherein the rotation by 0 or π is determined independently of the at least one scrambled output bit.

3. The method of claim 2 , further comprising using a pseudorandom noise generator to rotate the at least one constellation point.

4. The method of claim 2 , wherein the transceiver is a cable transceiver.

5. The method of claim 2 , further comprising transporting video.

6. The method of claim 2 , further comprising transporting video-on-demand.

7. The method of claim 2 , further comprising: receiving, in a second transceiver, the at least one scrambled output bit on the first carrier and the at least one scrambled output bit on the second carrier; and de-rotating, using a phase descrambler, the at least one constellation point associated with the at least one scrambled output bit.

8. The method of claim 1 , wherein the rotating is based on a plurality of predefined parameters.

9. A multicarrier communications transceiver comprising a bit scrambler followed by a phase scrambler, the bit scrambler operable to scramble a plurality of input bits to generate a plurality of scrambled output bits, wherein at least one scrambled output bit is different than a corresponding input bit, the phase scrambler operable to rotate by 0 or π at least one constellation point associated with the at least one scrambled output bit to reduce a peak-to-average power (PAR) ratio of a transmitted multicarrier signal, and a transmitter operable to transmit the at least one scrambled output bit on a first carrier of the transmitted multicarrier signal and transmit the same at least one scrambled output bit on a second carrier of the transmitted multicarrier signal.

10. The transceiver of claim 9 , wherein the rotation by 0 or π is determined independently of the at least one scrambled output bit.

11. The transceiver of claim 10 , further comprising a pseudorandom noise generator operable to rotate the at least one constellation point.

12. The transceiver of claim 10 , wherein the transceiver is a cable transceiver.

13. The transceiver of claim 10 , wherein the transceiver is operable to transport video.

14. The transceiver of claim 10 , wherein the transceiver is operable to transport video-on-demand.

15. The transceiver of claim 10 , wherein a second transceiver is operable to receive the at least one scrambled output bit on the first carrier and the at least one scrambled output bit on the second carrier and operable to de-rotate the at least one constellation point associated with the at least one scrambled output bit.

16. The transceiver of claim 9 , wherein the bit scrambler receives an input bit stream, and outputs the plurality of scrambled output bits to a constellation encoder.

17. The transceiver of claim 16 , wherein the constellation encoder outputs a plurality of constellation points to the phase scrambler.

18. The transceiver of claim 9 , further comprising one or more of a receiver, memory, a digital signal processor, a bit allocation table, a modulator, a pseudo-random number generator, and a symbol counter.

19. The transceiver of claim 9 , wherein the transceiver communicates over at least one of a communication channel, a pair of twisted wires, a fiber optic cable and a coaxial cable.

20. The multicarrier transceiver of claim 9 , wherein the rotation is based on a plurality of predefined parameters.

21. A method, in a multicarrier communications transceiver comprising a bit scrambler followed by a phase scrambler, comprising: scrambling, using the bit scrambler, at least one input bit to generate at least one scrambled output bit, wherein the at least one scrambled output bit is different than the at least one input bit; mapping the at least one scrambled output bit to a constellation point; rotating, using the phase scrambler to reduce a peak-to-average power (PAR) ratio of a transmitted multicarrier signal, the constellation point associated with the at least one scrambled output bit, wherein the rotating is equal to 0 or π; transmitting the at least one scrambled output bit on a first carrier of the transmitted multicarrier signal; and transmitting the same at least one scrambled output bit on a second carrier of the transmitted multicarrier signal.

22. The method of claim 21 , wherein the rotation by 0 or π is determined independently of the at least one scrambled output bit.

23. The method of claim 22 , further comprising using a pseudorandom noise generator to rotate the at least one constellation point.

24. The method of claim 22 , wherein the transceiver is a cable transceiver.

25. The method of claim 22 , further comprising transporting video.

26. The method of claim 22 , further comprising transporting video-on-demand.

27. The method of claim 21 , wherein the rotating is based on a plurality of predefined parameters.

28. A multicarrier communications transceiver, including a bit scrambler followed by a phase scrambler, operable to scramble at least one bit to generate at least one output bit, wherein the at least one scrambled output bit is different than the at least one input bit, operable to map the at least one scrambled output bit to a constellation point, and operable to rotate by 0 or π the at least one constellation point associated with the at least one scrambled output bit to reduce a peak-to-average power (PAR) ratio of a transmitted multicarrier signal, and a transmitter operable to transmit the at least one scrambled output bit on a first carrier of the transmitted multicarrier signal and transmit the same at least one scrambled output bit on a second carrier of the transmitted multicarrier signal.

29. The transceiver of claim 28 , wherein the rotation by 0 or π is determined independently of the at least one scrambled output bit.

30. The transceiver of claim 29 , further comprising a pseudorandom noise generator operable to rotate the at least one constellation point.

31. The transceiver of claim 29 , wherein the transceiver is a cable transceiver.

32. The transceiver of claim 29 , wherein the transceiver is operable to transport video.

33. The transceiver of claim 29 , wherein the transceiver is operable to transport video-on-demand.

34. The transceiver of claim 29 , wherein a second transceiver is operable to receive the at least one scrambled output bit on the first carrier and the at least one scrambled output bit on the second carrier and operable to de-rotate the at least one constellation point associated with the at least one scrambled output bit.

35. The transceiver of claim 28 , wherein the bit scrambler receives an input bit stream, and outputs the plurality of scrambled output bits to a constellation encoder.

36. The transceiver of claim 35 , wherein the constellation encoder outputs a plurality of constellation points the phase scrambler.

37. The transceiver of claim 28 , further comprising one or more of a receiver, memory, a digital signal processor, a bit allocation table, a modulator, a pseudo-random number generator, and a symbol counter.

38. The transceiver of claim 28 , wherein the transceiver communicates over at least one of a communication channel, a pair of twisted wires, a fiber optic cable and a coaxial cable.

39. The multicarrier transceiver of claim 28 , wherein the rotation is based on a plurality of predefined parameters.